JAMB 2015 · UTME · Q21

The graphical method of solving the equation $x^3 + 3x^2 + 4x - 28 = 0$ is by drawing the graphs of the curves

Worked solution (try it first)

Move the constant to the right: $x^3 + 3x^2 + 4x = 28$ .
Divide every term by $x$ : $x^2 + 3x + 4 = \dfrac{28}{x}$ .
So the roots are where $y = x^2 + 3x + 4$ meets $y = \dfrac{28}{x}$ , option D.

Report a problem with this question